Search PubMed⌕ Search

Biomedical subjects

A Wilcox

Publications and source records attributed to A Wilcox.

36 records · Page 2Linked to original sources
PubMed1996

Serum carotenoid concentrations and their reproducibility in children in Belize.

Suggestions that carotenoid-containing foods are beneficial in maintaining health have led to several studies of circulating carotenoid concentrations of adults. Because few data are available for children, we report serum carotenoid concentrations of 493 children in Belize. Carotenoid concentrations were determined as part of a survey of vitamin A status of children, most between 65 and 89 mo of age. Reproducibility was tested by collecting a second blood sample 2 wk after the first collection from a subset of children (n = 23) who consumed their habitual diet with no treatment during the interim. Predominant serum carotenoids were lutein/zeaxanthin and beta-carotene, which accounted for 26% and 24% of median total carotenoids, respectively. The three provitamin A carotenoids, alpha- and beta-carotene and beta-cryptoxanthin, constituted 51% of median total carotenoid concentrations. Partial correlations of each carotenoid with fasting retinol concentration indicated that beta-carotene had the highest correlation. Concordance correlation coefficients (rc) for fasting carotenoid concentrations determined 2 wk apart were > or = 0.89 for lycopene, beta-cryptoxanthin, and alpha- and beta-carotene. The rc for lutein/zeaxanthin and total carotenoids was lower, 0.59 and 0.68, respectively, because of higher lutein/zeaxanthin concentrations at the second sampling than at the first. The reproducibility of the concentrations suggests both that individuals have characteristic profiles and that serum carotenoid concentrations can be measured randomly over > or = 2 wk without significant bias.

Belize↗
PubMed1996

Xenobiotic metabolism genes and the risk of recurrent spontaneous abortion.

We examined the relation between spontaneous abortion and polymorphisms in two genes, glutathione S-transferase (GSTM1) and N-acetyltransferase (NAT2), which are involved in the metabolism of xenobiotics. In a case-control study of 29 women, we found that, among women with the GSTM1 null genotype, the odds ratio (OR) was 3.1 [95% confidence interval (CI) = 1.3-7.0]. There was less evidence of a relation with NAT2 [Mantel-Haenszel adjusted OR (ORMH) = 1.4; 95% CI = 0.45-4.3]. We sought to replicate the GSTM1 finding in an independent case-control study from New York involving 89 cases. We found an inverse association (OR = 0.8; 95% CI = 0.4-2.4). Taken together, these data provide little evidence of an association between GSTM1 or NAT2 genotype and risk of spontaneous abortion.

Abortion, Habitual↗
PubMed1995

Birth weight and perinatal mortality. A comparison of the United States and Norway.

OBJECTIVE: To compare perinatal mortality in the United States and Norway, using a new analytic approach based on relative birth weight. DESIGN: Comparison of linked birth and perinatal death records for US and Norwegian births from 1986 through 1987, the most recently available 2-year period. SETTING: Norway and the United States. PARTICIPANTS: A total of 7,445,914 US births and 105,084 Norwegian births. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Perinatal weight-specific mortality after adjustment for each country's own mean birth weight. RESULTS: The higher rate of perinatal death in the United States compared with Norway is due to an excess of preterm deliveries in the United States. Low-weight, preterm births comprise 2.9% of US births compared with 2.1% of Norwegian births. If the United States could eliminate this slight excess of preterm delivery, perinatal mortality in the United States would decrease to the level in Norway. Unexpectedly, the survival of newborns at any given birth weight is virtually the same in the United States and Norway when newborns' birth weights are considered relative to their own nation's mean weight. CONCLUSIONS: Low rates of perinatal mortality in the Scandinavian countries have usually been attributed to the heavier weights of their newborns. Higher mortality among US infants is in fact due entirely to a small excess of preterm deliveries. The lighter weights of US newborns at term appear not to affect perinatal survival. Furthermore, the apparent survival advantage of low-weight US newborns (used by policymakers as evidence of superior US intensive neonatal care) may be at least partly an artifact. When weight-specific mortality rates are adjusted to relative birth weight, low-weight newborns have the same survival in Norway as in the United States. The prevention of excess mortality among US infants depends on the prevention of preterm births, not on changes in mean birth weight.

Birth Weight↗
PubMed1994

GORA: a scoring system for the quantification of risk of graft occlusion.

Auditing the outcome from vascular surgery with regard to graft occlusion is made difficult by variations in the type of surgery performed and the case mix. These difficulties are compounded when attempting to compare units. In the present study we have attempted to develop a scoring system to predict the risk of graft occlusion, and thus compensate for these variables. Prospectively collected data from 214 consecutive patients undergoing vascular reconstructive surgery (233 arterial grafts) were analysed. Graft occlusion occurred in 82 patients (35.2%). Using a multivariate linear regression analysis of these data a five-factor, five-grade scoring system has been devised (GORA: Graft Occlusive Risk Assessment). Logistic regression analysis of the observed risk of occlusion with this derived score produced the following relationship between the odds ratio of occlusive risk and GORA score: (logeR/1 - R = (0.229 x score) - 4.165). The score was then validated in a different group of 186 patients (196 arterial grafts). In both groups the score was found to predict accurately the risk of graft occlusion (P < 0.001). There was no significant difference in the receiver operating characteristic curves between the estimation and validation groups.

Ankle↗
PubMed1993

Why do small twins have a lower mortality rate than small singletons?

OBJECTIVE: We propose an interpretation of the paradoxically better survival rate among low-birth-weight twins compared with low-birth-weight singletons. STUDY DESIGN: We used data from Belgian birth and death certificates for 1983 and 1984. The data include 229,964 singletons, 2175 first twins, and 2153 second twins. Weight-specific perinatal mortality rates of twins and singletons were compared; the birth-weight distributions were adjusted to a single mean and SD. RESULTS: After adjustment, mortality rates at every weight were higher for twins than for singletons. CONCLUSIONS: The appearance of better survival among small twins compared with small singletons disappears after adjustment to relative birth-weight. There is a large risk resulting from twinning that falls on all twins, regardless of their weight.

Birth Weight↗
PubMed1993

Comparative vascular audit using the POSSUM scoring system.

Comparative audit using overall mortality and morbidity figures can be misleading as they do not take into account variations in surgical procedure and patient fitness. To examine these effects we have compared vascular surgery in two differing hospitals, during a similar 9-month period, using the POSSUM scoring system. In one unit, 255 patients underwent vascular surgery with an operative mortality of 9.4%, and morbidity of 37.3%. In the other unit, 89 patients underwent vascular procedures with an operative mortality of 20.2% and morbidity of 47.2%. At first sight there appear to be significant differences in operative outcome between the two units. However, analysis using the POSSUM system predicts a mortality rate of 10.2% for unit A and 20.2% for unit B (morbidity rates of 38.4% for unit A and 50.6% for unit B). Receiver operating curve (ROC) analysis demonstrated no significant difference between the two units (see Table III). POSSUM analysis may be of use in comparative audit.

England↗
PubMed1986

Periosteal chondroma with atypical behavior in a 9-year-old black female: case report.

Periosteal chondroma is an uncommon benign cartilaginous tumor of bone reported most often in children and young adults but is as of yet unreported in a black child. This is a case of periosteal chondroma in a 9-year-old black female with unusual findings of short duration of symptoms; large size; suspicious x-ray appearance and; aggressive behavior. The lesion was histologically benign and has not recurred six years post curettage.

Bone Neoplasms↗
PubMed1986

Nylon sublaminar straps in segmental instrumentation for spinal disorders.

A new modification of segmental spinal instrumentation is in an early stage of research and development. Preliminary evidence is most encouraging with respect to the advantages of the relative safety of insertion of the nylon strap around the neural arch. The facility with which the insertion and tightening of the strap can be employed reduces the operation time significantly.

Bone Wires↗
PubMedDate not supplied

Caffeinated beverages and decreased fertility.

104 healthy women who had been attempting to become pregnant for three months were interviewed about their use of caffeinated beverages, alcohol, and cigarettes. In their subsequent cycles, women who consumed more than the equivalent of one cup of coffee per day were half as likely to become pregnant, per cycle, as women who drank less. A dose-response effect was present.

Adult↗
PubMedDate not supplied

Creating IPR and design value.

How a start-up company is overcoming competitive pressures by securing worldwide intellectual property rights and delivering customer delight.

Computer-Aided Design↗